1. Field of the Invention
The present invention relates to self-latching hinges, and particularly to such hinges wherein the latching force and part of the closing force is provided by the resilience of the hinge leaves.
2. Description of the Prior Art
Self-latching hinges have gained widespread acceptance in the building industry for use in the installation of cabinet doors and the like. Such hinges include a force providing mechanism which maintains the cabinet door closed and which assists in closing the door without the need for a separate latch or spring. Use of self-latching hinges eliminates both the cost of additional latch hardware and the even greater expense of installing such additional hardware.
In typical prior art self-latching hinges, a spring biased roller or wedge incorporated in one hinge leaf presses strongly against a notched hinge pin bearing sleeve on the other leaf. As the hinge members are rotated toward the door-closing position, the roller or wedge engages the bearing sleeve notch to then force the hinge closed. Some effort is required to open the hinge against the biasing force.
In most self-latching hinges of the type described, the roller or wedge biasing force is provided by a separate spring element mounted on one hinge leaf. Assembly is complicated because the spring must be highly prestressed to ensure that the cabinet door fully closes and because the spring acts at a very small distance from the hinge axis. Both hinge leaves must be formed of relatively thick metal to withstand this substantial spring force. One object of the present invention is to provide a self-latching hinge requiring no such spring element.
Another shortcoming of prior art self-latching hinges is the manner of attachment to the frame or closure. Most commonly, one of the metal hinge leaves was fastened by screws to the cabinet or door frame. By providing a hinge wherein one leaf may be formed of plastic, alternative means for attachment are available.